1. Field of the Invention
The invention relates generally to a method of installing an electronically conductive screw into a lead casting to form a battery terminal, but more specifically to methods of producing an assembled battery terminal with greater conductivity between the lead casting component and an electrically conductive post or screw component.
2. Description of the Related Art
Conventional battery terminals having lead casting components and electrically conductive post components are formed by pouring molten lead around the electrically conductive screw or post and allowing the lead to cool.
When an amount of lead is melted and becomes molten, its volume increases as it becomes less dense. Conversely, when lead cools its volume decreases as it becomes more dense. The decrease in lead volume from molten to solid can be described as lead shrinkage.
Accordingly, when molten lead is poured around an electrically conductive post and is allowed to cool, it shrinks and recedes from the adjacent surface of the post. As the volume of lead decreases during cooling, evacuated spaces between the lead casting and the conductive post or screw have been known to form. The evacuated spaces act as air pockets which are known to impair the electrical conductivity between the two components of the terminal.
In addition, a less than tight seal between the casting component and the electrically conductive post component has been known to allow minute quantities of electrolytes, liquids, corrosives and other substances associated with batteries, into the spaces between the post and the lead casting. The introduction of these substances between the components is known to cause corrosion of the post and further impair the conductivity of the combination.
It is also known that air bubbles become entrapped within a lead casting when molten lead cools. Trapped air bubbles have been known to make lead castings porous. In addition, conventional casting methods leave a rough exterior surface texture on the terminal.
A roughened terminal surface and trapped air bubbles can further reduce the amount of energy transferred from the available energy store, to which the battery terminal is attached, to the battery cable connected thereto.
Accordingly, a battery terminal of the type having an electrically conductive screw or post component encased within a ductile material casting manufactured in a manner to minimize air spaces between the screw and the ductile material has not been invented.
Further, a battery terminal of the type having an electrically conductive screw or post component encased within a ductile material casting manufactured in a manner to minimize air bubbles in the casting has not been invented.
Still further, a method of producing a battery terminal of the aforedescribed type, and having an enhanced conductivity between the screw or post and casting component in order to maximize the transfer of energy between the components, yet minimize the introduction of corrosives and other materials which would deleteriously affect the conductivity of the terminal, has not been invented.